Field of the Invention
This invention relates to systems and methods for preventing data loss in Redundant Arrays of Independent Disks (RAIDs).
Background of the Invention
A RAID (i.e., a Redundant Array of Independent Disks) is a storage technology that provides increased storage functions and reliability through redundancy. A RAID is created by combining multiple storage drive components (disk drives and/or solid state drives) into a logical unit. Data is then distributed across the drives using various techniques, referred to as “RAID levels.” The standard RAID levels, which currently include RAID levels 1 through 6, are a basic set of RAID configurations that employ striping, mirroring, and/or parity to provide data redundancy. Each of the configurations provides a balance between two key goals: (1) increasing data reliability and (2) increasing I/O performance.
When a storage drive component of a RAID fails, the RAID may be rebuilt to restore data redundancy. This may be accomplished by replacing the failed storage drive component with a standby storage drive component and copying and/or regenerating the lost data on the standby storage drive component. Ideally, the RAID will be rebuilt as expeditiously as possible to minimize the possibility that another storage drive component will fail during the rebuild and result in permanent data loss.
Unfortunately, when a RAID is being rebuilt due to a storage drive failure, additional stress is typically placed on the RAID that may cause other storage drives in the RAID to fail. This may be at least partially due to the fact that I/O may still be occurring on the RAID while it is being rebuilt. This may also be due to the fact that storage drives in a RAID may be of similar age, brand, size, etc., and when one storage drive fails, other storage drives may be on the verge of failing. The additional stress placed on the RAID during the rebuild process may be enough to induce these already-weakened drives to fail. Unfortunately, if another storage drive fails before the RAID has had a chance to rebuild, permanent data loss may occur.
In view of the foregoing, what are needed are systems and methods to prevent data loss in RAIDs. Ideally, such systems and methods will anticipate storage drive failures and proactively stress test storage drives and rebuild RAIDs before such failures occur. Further needed are systems and methods to intelligently rebuild a RAID array in a way that reduces the probability that another storage drive will fail during the RAID rebuild process.